Apparatus for heating ingots



F. A. CORBIN ETAL `APPARATUS FOR HEATING INGOTS L ,fl 4,

Patented May i3, 1947 APPARATUS FOR HEATING INGOTS l Fred A. Corbin, Gary, and Harry F. Netzhammer, Hobart, Ind.

Application November 20, 1942, Serial No. 466,342 7 claims. (ci. 26a-40) This invention relates to the heating of ingots and more particularly to apparatus for heating a plurality of ingots prior to rolling.

There are three types of soaking pits now in common use. The top fired pit with burner ports at one end and waste gas ports at the other tends to overheat the ingot tops and requires long soaking periods and excessive total pit time. The bottom red pit which has a burner firing vertically upward from the center of the floor and one or more waste gas ports in the Walls has the same disadvantage and also tends to burn out the brickwork of the cover. The burner port reduces the eiective' pit area and if an ingot falls over or into the port it will put the pit out of operation. The circular pit With tangentially fired multiple burners placed in a cistern-like annular enlargement near the pit bottom and a waste gas port leading downward through the center f the iloor gives the best heat distribution, but as the heat is applied. to only one side of the ingot there is a heat concentration'that has a tendency to wash that side. This pit is also impractical for any but large and heavy ingots with large bases which can stand of themselves; It also has the disadvantage of the large ports in the floor` It is an object of this invention to so supply direct heat to the surface of an ingot that the maximum distance of conduction will be approximately one-half the thickness of the ingot.

Another object is to reduce the temperature differential Within an ingot.

Still another object is to reduce the total time of heating, I

These and other objects will be more apparent after referring to the specification and attached drawings, in which:

Figure l is a cross sectional view of the furnace taken on line I--I of Figure 2;

Figure 2 is a plan view taken on line II-II of Figure 1;

Figure 3 is a view taken on line III- III of Figure-1;

Figure 4 is a view taken on line IV-IV of Figure 1;

Figure 5 is a view showing the heat condition within the ingot; and,

Figure 6 is a view similar to Figure 1, but showing a second embodiment of the invention.

Referring more particularly to the drawings, the reference numeral l indicates the ingots to be heated. The furnace consists ofv two side combustion chambers 2 which are formed by undercutting the side wall as shown in Figure 1 and a center combustion chamber 3. On each end wall are two side burner ports 4 and a center burner port 5. Since the flames tend to rise,

the ports are placed low to better heat the bottom of the ingot and to protect the cover Ill. The roof 9 of the combustion chamber 2 also keeps the `flames down and thus supplies more heat to the y clean-outs 8. The side combustion chambers are approximately one-half the size of the center combustion chamber so that approximately onehalf the heat is supplied to the ingot from each side. While one rectangular burner port is shown for each end 'of each combustion chamber, the ports may be shaped as desired to give desired llame characteristics and a plurality of ports having the same capacity as the single port may be substituted therefor. By making the side combustion chambers as shown, the pit cover l0 is smaller and the radiation losses will be less, especially when the cover is opened.

The flame from the side burner ports extends to the mid-portion of the pit and heats the lower portion of the ingots I and the Waste gases are drawn back along the bottom of the hearth to the waste gas ports E (see Figure 4). Since the roof is higher, the dames from the center burners rise as they leave the ports and supply heat to the upper part of the ingots as shown in Figure 3. Above the name are recirculating zones Il. There is also a recirculating zone above the ingots. The waste gas from the recirculating zones I is drawn down to the waste gas ports along the end Walls. The waste gas from the center name is drawn down and along the bottom ends of the ingots to the Waste gas ports. By constructing the side combustion chambers as shown, the small ingots may be leaned against the wall in the usual manner and yet the side surfaces will be exposed to the flame. By this arrangement the maximum surface of the ingot is exposed to the flame and the rate of heat conduction will be much greater than is usual. This enables most' of the heat to be added during the heating pe'- riod which is the time of maximum gas flow. After the control temperature is reached, the gas ilow is reduced and the soaking period begin@ Because of the small distance of heat conduction, this period will be short. The total pit time Will also be shorter than is usual. The operating conditions within the furnace may be adjusted by varying the gas and air ow of the individual burners, by varying the draft at the waste gas ports, and by controlling the length of flame.

Figure shows the heat condition within the ingot. The shaded surfaces indicate ame application and the small arrows indicate direction of heat conduction within the mass of the ingot. It will be apparent that the maximum distance of heat conduction will be from the outside of the ingot to the central portion thereof and very little longitudinal heat conduction will be necessary.

Figure 6 discloses a second embodiment of the invention which is suitable for heating ingots capable of standing without lateral support. This embodiment differs from the preferred embodiment by having the side combustion chamber 2' the same height as the center chamber 3'. Therefore, the flames from the side burner ports 4' will rise in a manner similar to that 'shown for the center burner. The construction of the-two pits is otherwise the same.

While two embodiments of the invention have been shown and described, it will be apparent to one skilled in the art that other modifications and adaptations may be made without departing from the scope of the following claims.

We claim:

1. An ingot heatingv furnace comprising a hearth for supporting rows of ingots with an open space on each side of each row, a plurality of burner ports located on each end wall of the furnace below the top of the space to be occupied by the ingots, each opposite one of the open spaces with at least one of said burner ports opening into each end of each space whereby flames are projected between and on each side of the rows of ingots, and at least one waste gas port at each end of the furnace.

2.An ingot heating furnace comprising a hearth for supporting longitudinal rows of ingots to be heated, a combustion chamber on each side of each row of ingots, va plurality of burner ports located on each end wall of the furnace below the top of the ingots, each opposite one of the combustion chambers with at least one of said burner ports opening into each end of each combustion chamber whereby flames are projected between and on each side of the rows of ingots, and at least one waste gas port at each end of the furnace.

3. An ingot heating. furnace comprising a hearth for supporting longitudinal rows of ingots to be heated, a combustion chamber on each side of each row of ingots, a plurality of burner ports located on each end wall of the furnace below the top of the ingots, each opposite one of the combustion chambers with at least one of said burner ports opening into each' end Of each combustion chamber whereby flames are projected from each end of the furnace between and on each side of the rows of ingots, and at least one waste gas port at each end of the furnace.

4. An ingot heating furnace comprising a hearth for supporting longitudinal rows of ingots to be heated, a combustion chamber on each side of each row of ingots, the combustion chambers along each side of the furnace being formed by 'undercutting the furnace side walls, a 'plurality of burner ports located on each end wall least one of said burner ports opening into each end of each combustion chamber whereby flames are projected from each end of the furnace between an'd on each side of the rows of ingots, and at least one waste gas port at each end of the furnace.

5. An ingot heating furnace comprising a rectangular hearth', a trench spaced from and extending along each side wall of the furnace, a coke breeze bed in each trench for supporting a row of ingots, a combustion chamber on each side of each row of ingots, a plurality of burner ports located on each end wall of the furnace below the top of the ingots, each opposite one of the combustion chambers with at least one of said burner ports opening into each end of each combustion chamber whereby flames are projected i from each' end of the furnace between and on each side of the rows of ingots, and at least one waste gas port at each end of the furnace.

6. An ingot heating furnace comprising a rectangular hearth, a trench spaced from and extending along each side wall of the furnace, a

coke breeze bed in each trench for supporting a row of ingots, a combustion chamber on each side of each row of ingots, the combustion charnbers along each side of the furnace being formed by undercutting the furnace side walls, a plurality of burner ports located on each end wall of the furnace below the top of the ingots, each opposite one of` the combustion chambers with atleast one of said burner ports opening into each end of each combustion chamber whereby flames are projected from each end of the furnace between and on each side of the rows of ingots, and a waste gas port at each end of each row of ingots.

7. An ingot heating furnace comprising a hearth for supporting rows of ingots with' an open space on each side of each row, a plurality of burner ports located on at least one end wall of the furnace below the top of the space to be occupied by the ingots, each opposite one of the open spaces with at least one of said burner ports opening into each of said spaces whereby flames are projected between and on each side of the rows of ingots, and at least one waste gas port at one end of the furnace.

FRED A. CORBIN. HARRY F. NETZHAMNIER. A

REFERENCES CITED The following references areof record in the A' ille of this patent:

UNITED STATES PATENTS Number Name Date 1,867,221 Hepburn July 12, 1932 1,915,470 Mawhinney June 27, 1933 2,052,187 Mawhinney Aug. 25, 1936 1,711,273 Manker Apr. 30, 1929 1,719,452 Ryding June 2, 1929 v1,897,008 Isley Feb. 7, 1933 1,926,714 Culbertson Sept. 12, 1933 2,177,733 Mawhinney Oct. 31, 1939 2,196,321 Morton Apr. 9, 1940 

